feat(banks): add trust bank credit card

[rapiz1]

add trust bank creditcard

I've attached an example statement in tests. It has "Previous Balance" and "Outstanding Balance" in transactions. I'm not sure if we should exclude them and enable safety check.

Notable difference for Trust credit card statement

1. For mutli-line transaction description, the description can start the previous line before the $amount line.
2. Number like +64.2 is CR. It's a prefix instead of suffix.
3. The statement date sometimes can be multiline as well. But I've only observed it with 2024 Dec. Maybe it's a misformat on Trust end. The proposed change cannot handle such case.

Resolves #183

[benjamin-awd]

If you add an optional capture group for suffix, it'll be able to catch the +682 in your statement -- the other transactions will default to negative

    TRUST = (
        rf"(?P<transaction_date>{ISO8601.DD_MMM})\s+"
        + SharedPatterns.DESCRIPTION
        + r"(?P<suffix>\+)?"
        + SharedPatterns.AMOUNT
    )

This means you won't need to modify the OPTIONAL_NEGATIVE_SYMBOL (I should probably put it only for the specific bank that needs it)

[benjamin-awd]

At the same time you can replace the description pattern with a custom one using a negative lookahead, so that it excludes totals:

TRUST = (
        rf"(?P<transaction_date>{ISO8601.DD_MMM})\s+"
        + r"(?P<description>(?:(?!Total outstanding balance).)*?)"
        + r"(?P<suffix>\+)?"
        + SharedPatterns.AMOUNT
    )

This will then allow the safety check to work.

[rapiz1]

Thanks! I wasn't familiar with the negative lookahead pattern until some searching. Is this a more readable pattern for descrpition?

+ r"(?P<description>(?:.(?!Total outstanding balance))*)"

I find lots of examples about negative lookahead but the "lookahead" is after some token. I cannot tell why the line you provide works because there's no token before the lookahead

[benjamin-awd]

I'm okay with modifying the transaction pattern regex here, but the pattern you mentioned doesn't seem to work 😕

There is actually a token before, which is \s+, but isn't reflected well in the multiline string unfortunately

it should work out to something like 12 Oct\s+(?!\s+Total outstanding balance)\s+.*
https://regex101.com/r/tQGJVE/1

[benjamin-awd]

Do you have an example of a multiline transaction that isn't currently well handled? I looked at your example statement but everything appears on a single line

[benjamin-awd]

This is great! It's weird that no other banks that I have so far give a total amount like this.

[benjamin-awd]

I think with the new regex pattern this bit isn't needed anymore

[benjamin-awd]

@rapiz1 Thanks for raising the PR! A few comments, but otherwise this looks pretty good